Epson ActionTower 3000 Computer - Manuel (Page 56)

6. Push the SIMM into the socket until it is seated firmly in the
slot. Then tilt it upright, as shown below, guiding the hole
at each end of the SIMM over the retaining post at each end
of the SIMM socket. If it does not go in smoothly, do not
force it; pull it all the way out and try again.
Installing and Removing Options 3-13